Unit concrete construction



April 21, 1931. H. M. KNIGHT 1,801,631

UNIT CONCRETE CONSTRUCTION Filed Feb. 17, 1927 vs Shets-Sheet 1 a @w \PFig. 2

April 21, 1931.

H. M. KNIGHT UNIT CONCRETE CONSTRUCTION 3 Sheets-Sheet 2 Filed Feb. 17,1927 ill 0 11 I ll ll Ill. N? U Inn-"Ln.

April 21, 1931. KNIGHT 1,801,631

UNIT CONCRETE CONSTRUCTION Filed Feb. 17, 1927 3 Sheets-Sheet 5connected to each other by the use of Patented Apr. 21, 1931 HERBERTKNIGHT, OF MONTCLAIR, NEW JERSEY UNIT CONCRETE. CONSTRUCTION Applicationfiled February 17, 1927. Serial No. 168,972.

This invention relates r01 unit concrete con structlon, using pre-castconstructional units, 7

and more specifically to that type of unit con struction in which thevarious elements are keys. One of theobjects of this invention is tounite the various units by means of a flexible key. 'Another'object ofthe invention isto unite .the units by means of while flexible ofitself, will combine with a cementitious filler, in a key-Way, toproduce an inflexible and stronger key. Still another object of theinvention is to" unite the units by means of a key which can beeasilyinserted inthe key-way, but which subsequently to such lnsertion becomesirremovable. Another ob ect of the invention is to unite the umts bymeans of a key which readily fits within the key-Way and which isextended to meet 0 and engage one or more bars of a reinforcing frame.Other objects of the invention will appear from the followingdescription and the accompanying drawings. a

The accompanying drawings Figs. 1 to 12, inclusive, are illustrative ofthe inventionand indicate the usual and preferred embodiment thereof.They are however illustrative only bodied, nor as excluding other'typesthan that indicated.

I illustrate my invention by the accompanying drawings in which, Fig. lisa crosssection of a joint between adjacent units on 5 the line 1-1, ofFig. 3. Fig. 2 is a. plan of the wire element of such a key. Fig. 3 is asection of such a oint on the line 3-3 of 1. Fig. 4 is a section of sucha joint on the line 4-4 of Fig. 1.v Fig. 5 is across-section of .a wallcomposed of a multiple of units, said units and the reinforcing membersof the said wall being inter-connected by wire keys. said section beingtaken on the line 55 of 6. Fig. 6 is a section of such a wall on theline 6-,6 of Fig. 5. Fig. 7 is a view of thedog employed. in connectionwith said key connected units. Fig. 8 is a plan of the wire element ofsuchan, interconnecting key. FigJQ is a section of a joint betweenunits, in which the wire element of the key is of the elastic type.

a key, which,

in said joint. Grooves 5, are

interlocking type of key. Fig. 11 is a section of a joint, the wireelement of which issingle and elastic, and which, like Fig. 10, is ofthe interlocking type, and Fig. 12 is a section of a joint, in which aninterlocking type of key is employed, and in which the slot or groove isfanged.

Referring to the drawings in which similar numbers refer to similar castslab, or unit, and 2, another unit, the said units being juxtaposed atthe joint 3. Longitudinal chases 4t, admit of a. mortar body alsolongitudinal of said joint. Dog-chases 6, admit of the introduction ofdogs, temporarily, or otherwise, bindingjuxtaposed or opposing units.Thickened edges 7, to said units, extend from the body portions 8,thereof. Bars, or rods, 9, extend longitudinal of said wires 10, engagesaid bars and extend outwardly of said grooves. 'Depressions 11, are inthe thickened edges of the said .units and mass concrete 12, engagessaid thickened edges and enterssaid depressions. Dogs 13, are positionedin said dog-chases. Reinforcingbars 14,'are within said mass concreteand hooked ends 15, engage and partially surround said reinforcing bars.A cementitious filler 16, fills the said grooves and surrounds andengages the said longitudinal bars and the. said wires. 7

In a structure made up of pre-castunits it is necessary that thejuxtaposed units be connected by a means which can at once be readilyand easily applied, and at the same time-permanently secure the saidunits together. Such connecting means should be one that lends itselfeasily to'the inequalities of the several units and of a suliicientlyfiexible character'to yield to these several inequalities withoutdisturbance or dislodgment of the assembled units. At the same timetheconnecting means should be such as to rigidly and immovably bind thesaid units when, and after the assembling is completed. These desirablefeatures are secured in my invention by the use of a jointingcombination, one element of which is a groove, or chase, cast in thethickened edge of thepre- Fig. 10 is a section of a joint, illustratingan parts :'1, is a pregrooves, and

tions of said wire elements enga ing either the bars longitudinal withinan alined groove of a juxtaposed unit, or the reinforcing bars of a massconcrete frame engaging, or connected to said units. A further elementis the cementitious filler or compound, which is introduced into thesaic groove and the said joint and which surrounds and engages both thebars within the grooves and the wire elements engaging said bars.

The wire elements are so constructed to engage frictionally the barslongitudinal of the grooves in the units, such friction being sufficientto retain the wire element upon the bars at any predetermined position.The usual form of the engaging wire element is that of two parallelportions which cross the joint between the adjacent units, the saidparallel portions diverging within the groove so as to constitute anopen area or areas in which are located the longitudinal bars, the saidwire element surrounding, or nearly surrounding the said bars and ongaging the superficies of the said bars at pre determined points. Thesaid surrounding wires, however, are rarely of such form, so far asthese areas are concerned, as to be in continuous linear contact withthe said bars, the contacts being at points rather than linear. As aresult of this dissimilarity of form, open portions result between thesurfaces of the bars and the wire elements, and these open portions arefilled with the cementitious filler of the groove.

In some cases the parallel portions do not remain on the same side of aline medial of the said key, but cross so as to reverse their positionsrelative to said medial line, thereby acting as a spring, and, by thepressing together of these reversed and parallel portions, result in thebars being more firmly held within and by the enclosing portions of thesaid wire element.

The key, so far as the longitudinal bars and the wire elements areconcerned, is usually assembled exterior to the units desired toconnect, and is subsequentlyinserted longitudinally into the alinedgrooves of the partially assembled, juxtaposed units. In some caseshowever it is impossible to insert the said key longitudinally of thesaid partially assembled grooves. in which event an interlocking keybecomes a necessity. Such an interlocking key, and of the wire type, isindicated in Figs. 10 and 12. In Fig. 10, the dotted line indicates aninitial position of one unit which is to be brought laterally into finaland permanent position,

the latter being indicated by full lines. Other dotted lines indicatethat of the key, composed of rods and connecting wires, the latter ofarched or curvilinear form, one of the rods is located in the grooves ofthe one of the units which has been definitely positioned, and the freeend of the key has been raised until the curvilinear connecting wireelement is in contact with the upper lip of the groove of the saiddefinitely positioned unit. As soon as the upper lip of the oppositeunit sh all have been brought into contact with the rod element of saidfree end of said key, the said free end is allowed to fall and to restupon the lower lip of the groove of the unit being positioned. Furthermovement of said unit results in said rod and its curvilinear connectingwire element dropping automatically into the groove of said moving unit,until, when said unit is finally and permanently located, the said keyis embedded within the juxtaposed and opposite grooves of said adjacentunits, and is surrounded by the eementitious filler which has beenintroduced into said grooves before the assembling of the said units.The keys cannot be withdrawn, and the hardening of the said cementitiousfiller in the said grooves completes the work of binding said unitsfirmly and immovably together.

Fig. 12 illustrates another form of such interlocking key. In thisinstance the form of the groove is fanged, that is it is composed of twodivergent areas, situated on either side of a medial line and connectedwith a common throat. The key, in this instance, before insertion in thekey-way, is practically a straight line key, the portion of the wireelement at either end which joins the areas surrounding the longitudinalbars being bent back along the centre line of the key. When the keyenters the groove, the throat of which is made of just sufficient widthto admit of the passage of the longitudinal rods and their wireelements, it passes into the groove until it strikes the tongue, orfork, of the fang, upon which occurring the longitudinal bars begin toseparate and pass each into its own divergent area of the fang. This isoccurring at the same time, and in the same manner, in the alined grooveof the juxtaposed unit, the pressure or weight, or both of these twounits forcing the rods apart and into their said resident areas. Theportion of the wire element connecting the said two rods within eachgroove, is gradually straightened out, until from aposition practicallyparallel with the central wires, it becomes oblique thereto, approachingthe normal. The subsequent hardening of the filler, as in the casebefore, rigidly and permanently keys the joint.

As the assembling of units and keys of these general forms demands agreat degree of accuracy in its performance, it is very necessary thatthe several units shall register accurately before and during theplacing and hardening of the keys. To assure such accuracy ofregistration, dogs are employed for initially positioning the units,these dogs occupying depressions cast in the units, and, in order thatthe several units may be placed without interference these depressionsor chases are so cast as to be in all cases beneath the edges, or othersur-' crete frame is employed, the conditions may be so modified, as,that, in addition to uniting uxtaposed units together, the entlrestructure, units, whether ad acent or oppositely disposed, and thereinforced concrete frame can be united in a manner that makes the keysemployed, a distinct and effective means of initial and permanentconnection. In such cases the wire element of the key is madedissimilar, so far as the inner and outer members thereof are concerned,the inner, or part within the groove, remaining similar in form andpurpose to that above set forth, in this description, while the outerportion, or that portion exterior to the groove, is so altered as toopen up the wires composing the element, and at the same time theextremities are so formed as-to embrace the reinforcing members of themass concrete frame.

What I claim is 1. In a construction, the combination of a multiple ofpre-cast units, thickened edges to said units, re-entrant grooves insaid edges, and keys in said grooves, one element of said keys beingrods within, and longitudinal of said grooves, another element beingwires, said wires engaging said rods and spanning said joints and athird element being a cementitious filler within said grooves andsurrounding said rods and said wires.

2. In a construction, the combination of a multiple of pre-cast units,re-entrant grooves in said units, a mass concrete frame, re-inforcingmembers in said concrete and keys connecting said units and saidre-inforcing members.

3. A building construction comprising in combination with building unitsadapted to be assembled in a structure, said units having registeringgrooves in their abutting edges and which together form a substantiallyclosed pocket longitudinal of the unit and open at one end of saidgrooves and units upon assembly of said units, and a re-inforcfrom thesaid dogs,

ing device entirely within said pocket slidable into positionfrom theopen end thereof and extending from one groove unto the other of theabuttlngunits.

4. A building construction comprising in from one groove into the otherof thea'butting units for re-inforringthe 'key.

5. A building construction comprising in combination with building unitsadapted to be assembled in a structure, said units having re isteringgrooves in their abutting edges and Which together form a substantiallylongitudinally closed pocket upon assembly of said units, longitudinalre-inforcing bar in each of said grooves thereof, a reinforcing deviceentirely within saidpocket with a portion thereof surrounding each ofsaid bars and slidable into position from the open end of the pocket onthe bars and eX tending from one groove into the other of the abuttingunits. 7

6. A building construction comprising in combination with building unitsadapted to be assembled in a structure, said units hav-' ing registeringgrooves in their abutting edges and which together form a substantiallylongitudinally closed pocket upon assembly of said units, a longitudinalreinforcing bar in each of said grooves thereof, a

cement-itious key in said pocket filling both said grooves, are-inforcing device entirely within said pocket with a portion thereofsurrounding each of said bars and slidable into position from the openend of the pocket on the bars and extending from one groove into theother of the abutting'units for reinforcing the key.

7. A building construction comprising in combination a multiple ofpre-cast units, thickened edges to said units, re-entrant grooves insaid edges, keys in said grooves, one element of said keys being rodswithin and longitudinal of said grooves, and another element beingwires, a mass concrete frame, and re-inforcing rods in said frame, saidwires engaging said rods in the grooves and said rods in the concreteframe.

,8. A building construction comprising in combination a multiple ofpre-cast units, edges of said units having re-entrant grooves therein,and a key in said grooves comprising a resilient metallic member havinga less cross sectional area than said grooves so as to have latitude forresiliently engaging portions of the surfaces of said grooves forpositioning said units With respect to each other and constituting are-inforcing member for the joint between said units.

5 9. A key for uniting units of building construction having re-entrantgrooves, comprising a ire bent to provide enlarged end portions forinclusion in the enlarged portions of the grooves, and said Wireproviding a narrow connecting portion between said enlarged portions forpassing through the restricted portion of said grooves, whereby saidunits may be held against separation by insertion of said Wire key inthe opposed reentrant grooves of said units.

Signed at New York, in the county of New York and State of New York,this 16th day of February, A. D. 1927.

HERBERT M. KNIGHT.

